If you see any brother or sister commit a sin that doesn’t lead to death, then you should pray for them, and God will give them life. I’m talking about someone whose sin doesn’t lead to death. There is a sin that does lead to death. I’m not saying you should pray about that.
I used to say insulting things about Jesus. I tried to hurt his followers, and I even used violence against them. But God had mercy on me because I did those things without knowing any better. I wasn’t a believer.